Pneumatic motor



April 8, 1924:

T. SMiTH PNEUMATIC MOTOR Filed Dec. 19. 1921 INVENTOR. T/YO/VAS SM/Tfl.

2 f ATTORNEY Patented Apr. 8, 1924.

THOTJIAS SMITH, OF OAKLAND, CALIFORNIA.

PNEUMATIC MOTOR.

Application filed December 19, 1921. Serial No. 523,374.

To all whom it may concern:

Be it known that I, THOMAS SMITH, a citizen of the United States, and a resident of Oakland, county of Alameda, and State of California, have invented a new and useful Pneumatic Motor of which the following is a specification.

My invention relates to a turbine adapted to be actuated by air under pressure.

An object of the invention is to provide a pneumatic turbine which is cap-able of operating in a highly eflicient manner with a comparatively small volume of air at a low as well as a high pressure.

Another object of the invention is to provide a turbine of the character described which may be built in extremely small sized portable units.

A further object of the invention is to provide a turbine with the foregoing features, which is extremely simple in construction, inexpensive to manufacture, durable yet quite light in weight.

The invention possesses other "bbjects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of my invention which is illustrated in the drawings accompanying and forming part of the specification. It is to be understood that I do not limit myself to theshowing made by the said" drawings and description, as I may adopt variations of the preferred form within the scope of my invention as set forth in the claims.

Referring to said drawings:

Figure 1 is a longitudinal section of the turbine.

Figure 2 is a transverse section of onehalf of the turbine taken on the line 22 of Figure 1.

Figure 3 is a fragmentary view of the inner casing.

Figure 4 is an end view thereof.

Figure 5 is a fragmentary view of the outer casing.

Figure 6 is a developed view of a portion of the rotor showing the arrangement of the buckets thereon.

Figure 7 is a perspective view of a set of buckets. Y i 7 Briefly expressed the turbine in its present embodiment comprises an inner and outer casing between which is mounted a rotor provided withblades and adapted to The inner casing be rotated by air directed against said blades through nozzles extending from the inner casing, the latter being adapted to contain air which is maintained sure. After striking the blades the air escapes from the rotor and impinges against angularly disposed surfaces formed in the outer casing, thereby causing a reaction of the air pressure in a manner tending to increase the torque of the rotor. A similar reaction of the air pressure, to the advantage of the torque of the rotor, isaiforded by means of tangentially disposed blades provided on the exterior portion of the inner casing lying within the rotor. -Within the inner casing is rotatably mounted a shaft which is connected to the rotor and affords means for transferring the torque of the rotor to an extraneous member. Means are also provided on the shaft for preventing the collection of foreign matter within the inner casing and at the same time aiding the rotation of the shaft.

A detailed description follows:

The turbine in its present embodiment is in the form of a portable unit and comprises an outer casing 2 threaded at opposite ends for attachment with the closures or heads? and 4C. Arranged within the casing 2 and spaced therefrom is an inner casing 6 having one end 7 threaded for attachment with the head 4, and the. other end 8 closed by a member 9. Lying within the inner casing and rotatably mounted in ball-bearings l0 and 12 disposed in the heads 3 and 4, is. a shaft 13 one end 14: of which extends through the, head 3. The bearing 12 in which the end 15 of the shaft engages is adapted to take up end thrust of the shaft as well as lateral thrust.

Fixed to the shaft by means of the end wall 17 which engages the threaded portion 18 of the shaft and abuts, against the shaft collar 19, is a. rotor2l which is positioned in the annular chamber 22 formed between the cylindrical casings 2 and 6. The rotor is arranged to be closed at its ends by means of said wall 17 and an end wall 23 through which the casing 6 extends, a

bearing member 24; being fixed to said casing for engagement with the latter end wall.

is adapted to be sup? plied with air under pressure, and is pro "1 1 1 with a r inlet connection 26'by at a constant pres- Bit? which may be had the proper communication with a suitable source of compressed air supply whereby the pressure Within the inner casing may be maintained at a substantially fixed value. In order that there may be no leakage of the air in the'casing 6 where the shaft 13 passes out, a suitable packing 27 is interposed between the shaftcollar 1.9 and the cap member 8. Extending tangentially from the inner casing and communicating with the interior thereof are a plurality of circiunferentially spaced nozzles 28 through which. the compressed air from the inner casing is adapted to be forcibly dischargedagainst buckets 29. fiXed Within the rotor. The bucket-s are arranged in circumferentiall spaced sets, each set comprising a plurality of blades 31 extending longitudinally of the rotor axis and arranged edge to edge and: forming a series of reentra.nt angles. The,cor-responding portions of the blades of the'di-fl'erent sets are circumferentially; aligned, and the nozzles are so positioned that the,.jet of air emitted by them will enter between convergent blades of one set and thence r'ebound against the divergent blades of the succeeding set. Upon reaching the base of the divergent blades the jet is allowed to escape from the rotor through, discharge passages 32, as clearly indicated in Figure 6. It will be evident that the rate of rotation of the rotor will be determined by the amount ofpressure maintained inside casingfi, since the velocity of the air discharged through the nozzles in directly determined by such pressure.

Formed in the inner side of the outer casing 2 in the direct path ofthe jets of air issuing from the rotor discharge-passages 32, are a plurality of depressions 33 defining angular surfaces 34 against which said jets are adapted to strike and thereby, cause a reaction of the air against the rotor in a manner tending to increase the'torquethereof. After the remaining energy of the air is spent in the said reaction, the air will discharge through suitable openings 36 provided in the casing 2.

Owing to the fact that aportion of the air received by the buckets directly" from the nozzles is unable to immediately escape through the apertures .32, itrebounds in a stream against the inner casing and means have been provided to utilize this rebounding action of the air to increase-the effective torque of the rotor. Extending tangentially from the casing fi parallel tofa-nd between adjacent nozzles are -.blades;;39- betwe n, which and the-outer side 1 ofzsaidzcasing the air rebound efmhi said; bucketsis caught and its flow directed back against the buckets; in; the direction: of: their rotatiom Thus the ener remaini- 1n the air escaping- "inwardly' and outwardly fromthe buckets is utilized to aid in overcoming frictional drag on the rotor and increasing theturning effort thereof.

In order that there will be no collection of foreign matter within the inner casing and thereby impair the unrestricted flow of the air through the nozzles, there are preferably fixed on the shaft one or more sets of blades ll, which serve to agitate the air contained within the casing and thus cause any foreign particles such as fibrous matter to be kept inmotion. The blades 41 are preferably positioned at such an angle to the air moving through the casing that they will tend to rotate the shaft in the same 'direction asthe rotor.

A handle 42 is preferably attached to the outer casing in order to facilitate the handling of the turbine. In connection with the foregoing it may be stated that although I have shown a portable unit, it is obvious that the turbine may be designed as a stationary unit and such desired and necessary changes made in the construction as the conditions may warrant.

I claim:

1. In a pneumatic turbine, an inner casing adapted to contain air under pressure, an outer casing surrounding said inner casing and'spaced therefrom, a rotor revolubly mounted between said casings for movement relative thereto, blades mounted on said rotor, nozzles on said inner casing through which the air in said casing is discharged against said blades, and deflecting surfaces on said inner casing against which the air discharged from said blades impinges.

2. In a pneumatic turbine. an inner casing adapted to contain air under pressure and provided with a plurality of discharge openings, an outer casing surrounding said in ner casing and spaced therefrom, a rotor mounted between and revoluble with respect to said casings; and surrounding said openings, a plurality of blades on said rotor against which the air passing through said openings is: adapted to be discharged, and deflecting surfaces on the exterior ofsaid inner casing and on the interior of said outer casing against which the air discharged from said blades will impinge.

3. In a pneumatic turbine, an inner casing adapted to contain air under pressure and provided with a plurality of discharge openings, an outer casing surrounding and spaced from said inner casing provided with an outlet, a shaft rotatably mounted in said inner casing, a rotor mounted between said casings fixed to said shaft and p-rovidedwith closed ends, buckets mounted onsaid r0- tor against which the air from saidopenings is-adapted to impinge; and passagesin said rotor-through which-the air after impingingagainst said buckets isadapted to discharge from saidrotor.

4. In a pneumatic turbine, an inner: casing adapted to contain air under pressure and provided w openings, an outer casing surrounding and spaced from said inner casing and provided with an outlet, a shaft rotatably mounted Within said inner casing, a cylindrical rotor revolubly mounted between said casings and fixed to said shaft, blades Within said rotor against which the air from said discharge openings is adapted to im ringe, pas sages in the peripheral wall 0 said rotor through which the air after impinging against said blades is adapted to discharge from said rotor, and means provided on the inner side of said outer casing forming a succession of angular surfaces against which the air from said passages are adapted to impinge.

5. In a pneumatic turbine, a casing adapted to contain air under pressure and provided With a plurality of tangential passages through which the air in said casing may discharge, a rotor surrounding said casing and provided on its inner side with a plurality of blades against which the air from said passages is adapted to impinge, and a plurality of tangentially extending blades fixed on the outer-side of casing and transversely aligned with said passages and said first blades.

6. In a pneumatic turbine, a casing adapted to contain air under pressure, a ro-, tor surrounding said casing, a plurality of buckets fixed on the inner side of said rotor, a plurality of nozzles extending tangentially from said casing and through which the air from said casing is adapted to be discharged against said buckets, and a plurality of blades extending tangentially from said casing in alternate relation with said nozzles.

7. In a pneumatic turbine, a casing adapted to contain air under pressure, a plural-.

ity of nozzles extending tangentially from said casing, an outer casing surrounding said inner casing provided with an outlet, a shaft rotatably mounted within said inner casing, a rotor disposed between said casings having closed ends and fixed to said shaft, a plurality of buckets arranged within said rotor against which the air from said nozzles is adapted to be directed, blades extending tangentially from said inner casing alternately with said nozzles, discharge passages formed in said rotor alternately with said buckets, and means provided on the inner side of said outer casing forming a succession of angular disposed surfaces against which the air from said passages are adapted to impinge.

8. In a pneumatic turbine, a rotor, a plurality of circumferentially spaced sets of buckets fixed on the innner side of said ro-' tor, each of said sets com rising blades arranged to form a series 0 re-entrant angles ith a plurality of discharge progressing in the direction of the longitudinal 8X13 of the rotor the corres )ondm 7 portions of the blades of one set being circumferentially aligned with those of the other sets, passages formed in said,rotor communicating with the base of each bucket and through which air may be discharged from the interior to the exterior ofthe rotor, and means for directing'air. under pressure'tangentially against said buckets. I

10. In a pneumatic turbine, an inner casing adapted to contain airunder pressure, an outer casing, heads closing both ends of said outer casing and one end of said inner casing, a cap closing the other end of said inner casing, a shaft rotatably bearing in said heads and extending through said cap, a rotor revolubly mounted between said casings and fixed to said shaft, and nonfriction means in one of said heads for receiving the end thrust of said shaft.

11. In a pneumatic turbine, a fixed casing adapted to contain air under pressure, a shaft rotatably mounted within said casing, a rotor revolubly mounted about said casing and fixed to said shaft, blades on said rotor, and passages in said casing through which the air may be discharged against said blades.

12. In a pneumatic turbine, a fixed casing adapted to contain air under pressure; a rotor revolubly mounted on said casing; blades on said rotor and nozzles on said casing through which air pressure may be dis charged against said rotor blades.

13. In a pneumatic turbine, a casing adapted to contain air under pressure; a rotor revolubly mounted on said casing; a plurality of circumferentially spaced sets of buckets fixed on said rotor, each of said sets comprising blades arranged to form a series of re-entrant angles progressing in the direction of the longitudinal axis of the rotor, the corresponding portions of the blades of one set being circumferentially aligned with those of the other sets; and nozzles in said casing through which air pressure may be discharged against said totor buckets.

14. In a pneumatic turbine, a casing adapted to contain air under pressure; a plurality of nozzles in said casing through IUD which air under pressure may be discharged; a rotor'revolubly mounted on said casing; and a plurality of blades on said rotor against Whichthe air pressure from said casing nozzles is adapted to impinge.

15. In a pneumatic turbine, a casing adapted to contain air under pressure; a rotor revolubly journaled on said casing; a

plurality of buckets fixed on said rotor; a plurality of nozzles extending tangentially j from said casing through which the air from said casing nozzles is adapted to be dischargedagainst said buckets; and means on the periphery of said casing, adjacent said nozzles, against WlllOhELlI' pressure, reboundingfrom said rotor buckets may impinge.

In testimony whereof I have hereunto set my hand at Oakland, California, this 13th day of December, 1921.

THOMAS SMITH. 

